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Topic: Etching and lithographing (Read 7334 times)

Well, closest I've come to metal work lately has been experimenting with etching and lithographing using common non-toxic and kitchen materials.

I started off trying aluminum foil per some internet suggestions and etching with coca cola, and using a lot of different other stuff for a resist. Mainly castille soap -- also an online suggestion. But that didn't work well or consistently for me. So I started looking for a grease that was meltable just a little above room temperature, and after a little research settled on coconut oil, which seemed to work well using a brush. as a resist. Warm water removed it

I tried coca cola and white vinegar as mordants, but again consistency was difficult. I did manage a few prints of birds for my neices for christmas -- one owns a cockatiel and the other is a biologist who does field research. They were okay as a start, but I didn't like some things about using foil for a printing plate -- mainly that it had to be placed on a larger acrylic sheet for inking, and the ink would get on the acrylic, which meant you had to cut the border of the image down. It also didn't leave the nice embossed edge a real etching plate does when run through a press.

So I decided to experiment with aluminum plate -- which alloy would work best, I didn't know. I think Reynolds aluminum foil, which seemed to work well is 8111 alloy -- virtually impossible to get. So I decided to just try some "generic" aluminum plate available from a local sheet metal bender -- he didn't even know the variety he had.

This didn't seem to work well using the old method I'd tried which was to lay down the resist, and then etch. But eventually I hit on the discovery that etching wasn't really required, and the main effect was a litho process, not an etching process. Litho depends on the difference in adhesion of oil based ink on a hygroscopic surface vs a water repellant surface. I found by experiment that cleaning and abrading the plate with scotch brite, then immersing in coca cola coated it with a hygroscopic surface evenly. Then drawing on that with 6B soft pencil created a water repellent line surface which increased in its oil holding capability with subsequent inkings. A lot of other kinds of markers didn't work as well for me.

This was pretty cool and I experimented with prints of an image of fossils, and an alligator swimming -- the last drawn from film I'd taken when I lived on my houseboat in Florida 20 years ago. I was able to get a good impression of the plate into the paper even without an etching press -- just using a spoon to rub the image in.

So there you go, my only metal working to date, this year at least. Aluminum foil, unknown alloys and coke.

Hi guys, good to be back in this small way metal working. Thanks for the kind comments on the artwork -- it's been a long time since I did that. Kinda got hooked back into it when I dropped into a local little art school for an opening -- they had a new print shop, and I asked if they ever did etchings. They said no the chemicals (nitric acid especially) wasn't something they wanted to fool with. So I said it probably was possible to do with household stuff -- remembered something I'd seen on the Internet. They said hey, that would be great if you would figure that out and maybe teach a class here in that.

So I took it on as a challenge. Kinda enjoying it.They let me use their 24" x 48" etching press today, and supplied me with good paper, and a place to work, so I tried a really big plate today (relatively) 22" x 30" print -- full sheet of the paper. But it didn't work out -- pretty tricky on that scale to get it inked evenly without overdoing it. Oh well, it was fun, I'll have another go at a big print shortly.

My tiny work shop is the usual total mess and I'll need to do something about that before I can get back into it and finish that lathe. I mean literally get back into it! The printing on aluminum has all taken place in the kitchen and dining room table, except for todays print attempt.

I'm also thinking about trying electrolytic etching. I know it works well for engraving -- Rob, you've done a lot of that. It'd be interesting to see how it works for etching printing. I don't see why the old style heavy acids are necessary. And steel might make a good and long lasting etching plate.

Hi Vtsteam I also am interested in etching I have bought some photopolymer material from capefearpress and have been gathering up all that I need for some salt water etching like laser printer, transparencies, and washing soda. I have a plate burner downstairs that should be able to expose it I hope (carbon arc) used 20 years ago printing in the basement on the Multi.

If there are any comercial printshops in your neck of the woods, you might drop by and see if they'd be willing to donate a few used offset plates to your cause. These plates are large (depending, obviously, on the size of the machine) ~1mm thick aluminium sheets. The plates for repeat customers are usually stored for future use, but the plates for one-off jobs are typically just recycled.

That's very interesting, Tom -- I read the article you linked to. I eventually realized that what I was doing was lithography and not etching, which was a little disappointing at first. In etching you are making recesses that accept the ink, while in lithography you are making slightly raised areas that repel water, and so accept oil based ink. So the difference is in one it's a sunken image, and in the other it is a raised image.

The big difference is in how you ink them. In an etching you put ink all over the whole plate, and then remove it gradually from the high areas by wiping, which become the white space on the finished print. In lithography, you are rolling ink on the high areas (you hope) because the other (white) areas stay damp with water and repel the ink. Of course if you don't wipe the whole plate carefully and frequently with a water sponge before rolling each time, the ink sticks everywhere, and the image can be ruined. That's what happened yesterday.

I would still like to try etching, and I'm thinking the electrolysis method that Rob used to engrave would work as well as an acid bath. I think an etched plate is much more robust than what I've been doing -- even if you mess up a print, you can always clean back the plate because the image is incised. Doing the litho prints that I am, the plate can easily get ruined if you mis-ink it. I find that I have to do the artwork and print immediately, also -- the plate won't work after a day. That's an area that my be something I can improve upon, since commercially, litho plates can last longer, and be re-used, I think. I'm thinking the addition of gum arabic in the coke, might make the plate last longer.

Anyway, interesting stuff, and I would definitely like to try "real" etching with electrolysis, as well as improve the success rate of simple litho.

Josh, thanks. Yes I used to work on a newspaper in the '70s with our own press, and I remember the photo plates -- pretty thin, though <1 mm-- people used to patch their cars rust holes with used plates.

There are no print shops here, and the aluminum sheet I bought was only $17 and is infinitely re-usable for litho (not etching).

For etching, I think steel might be good -- it was used traditionally, and supposedly gave the longest lasting print runs, compared to copper and zinc, which were the other traditional types used for etching plates. Steel can definitely be engraved by electrolysis.

Lithography takes it's name from the Greek Lithos - meaning stone. Lithographic prints were originally taken from flat limestone, the surface of which had been treated selectively to absorb or repel inks. At the simplest level it could be a drawing using a wax crayon.

No doubt the surface of lithographic plates demonstrate the same differential quality

Andrew, yes, traditionally they did use stone plates and lithographic crayons for the image and a weak acid solution combined with gum arabic to etch after the image was drawn. The gum arabic stayed behind on the etched stone face in the white areas and formed the hydroscopic layer. The crayoned areas were hydrophobic and the oil based inks stuck to that.

One major difference in what I've been doing (besides the aluminum plates) is in pre-etching, rather than etching after the image is in place.

Another is using coca cola, which has phosphoric, carbonic, and citric acids, and probably gum arabic as well. Easy to buy a made up solution ready to go!. And the bubbling action does sometimes act usefully to make patterns, or clean up areas when used on a brush, where you may have a stray line or blot.

As I was just writing this my wife said a package had arrived -- and it's gum arabic. I won't be using "real" stone litho plates, however. Not too easy to come by here.

Well we started with large (chip) potatoes which worked remarkably well cut in half, then went on to lino (linoleum) which the youngsters here have probably never heard of - you used to be able to get special kits of cutters to carve your design

I won't be using "real" stone litho plates, however. Not too easy to come by here.

Steve..... Isn`t half of Washington DC made with Vermont marble.....

Cheers, pot-stirring Joe

Could be, Joe, but I think they used limestone for the litho plates, and though closely related, marble is the metamorphic form of limestone. I think I remember back in the rock collection days as a kid, you'd test for limestone with vinegar to see if it bubbled up -- marble wouldn't do that. So my guess is that there is probably a similar difference if trying to etch it with a weak acid and lay down gum arabic. Who knows? What I do have lots of on my land is shale. But of course, none of it smooth enough to use as a plate. Lots of slate nearby, though not on my land -- and that is the similar metamorphic form of shale.

Back in grade 8 art class we used floor tiles that we would carve patterns into that were then inked the paper was just rolled over by hand.

Still very popular today in the form of, yes, linoleum block. That's linoleum glued to about a 1" thick birch ply block. I just happened to see some linoleum printing yesterday down at the school studio. And it wasn't even mounted on a block. Just the tile-like piece with burlap backing. So it's still going on today.

Linoleum gets it's name from linseed oil, btw, which it is made from. Oleum means oil.

Well we started with large (chip) potatoes which worked remarkably well cut in half, then went on to lino (linoleum) which the youngsters here have probably never heard of - you used to be able to get special kits of cutters to carve your design

I once tried the potato printing thing when I was younger Andrew, and it worked great, as I remember it. Not a very big print, but certainly an affordable and easy to carve printing block. You could erase and start over with another slice! Like when you found out your initials printed backwards.

Did you guys ever carve soap into sculptures? Ivory actually used to run contests for carved soap.